To counter shoulder browsing, or advertisements served on multi-family computers and apparatus, advertisement block extensions and plugins (like AdBlockPlus) can discontinue a number of the advertising from coming through.
Some propose using multi-user user experience to be partitioned by accounts for Chrome within the family, but you can not do this for children under 13.
You will have to do your shopping through a VPN service to give it a distinct IP to log and monitor related to your red seat searches for retargeting trackers using your IP.
The measures an average consumer must choose to be able to search in secret have gotten so extreme, it makes us look like dishonest offenders — but for the want not to spoil surprise present-offering, or private buying.